1. Field of the Invention
The invention relates to micromechanical, micro-electromechanical (MEMS) or micro-opto-electromechanical (MOEMS) components. More particularly, this invention pertains to a method of manufacture of such a component as well as the resultant component.
2. Description of the Prior Art
Active structures of micro-electromechanical components (MEMS) or micro-opto-electromechanical components (MOEMS) are often hermetically encapsulated to minimize environmental influences such as moisture and contaminants (e.g. dust). (“Active structure” should be understood to mean, in particular, movable structures, optical structures or structures having both movable and optical components such as movable mirrors. The term “active region” denotes the region or volume of the component in which the active structure lies or moves.) Hermetic encapsulation can also be employed to set a specific internal pressure in the region of the active structures. This is particularly advantageous in components whose functioning is dependent on a defined internal pressure (e.g. acceleration sensors and gyroscopes (rate-of-rotation sensors)). Fabrication of MEMS or MOEMS components generally takes place at the wafer level so that production can be implemented as cost-effectively as possible. Joining processes that are often carried out can be performed, for example, on the basis of direct and anodic bonding processes.
Leading electrical contacts out from the hermetically tight region of the component to make contact with specific parts of the component (e.g. the active structure) is difficult from the standpoint of fabrication. Various possibilities exist. Electrical contacts can be realized, for example, by laterally extending semiconductor layers produced by implantation or diffusion methods that have a low sheet resistance. It is additionally possible to accomplish this by means of patterned conductive layers covered with a planarized passivation layer. Alternatively, the electrical contacts can be led out from the component through a plurality of vertically extending plated-through holes.
DE 102005015584 describes a method for production of a component in which the active region and, hence, the active structure, of the component is isolated from the environment (as far as contaminants and moisture are concerned) before contact holes are made. Electric current required for operation and signals generated by the active structure are respectively fed to the active structure and tapped off via the contact holes and the adjacent conductive structure layer. However, this does not permit any crossover of interconnects. In particular, it is not possible to make contact with regions (e.g. electrodes) lying within a movable structure that is closed (in a component layer plane) with a tolerably small area requirement. Therefore, the movable structures 6 in MEMS 2 realized by this technology often have openings 3 for the interconnects 4 to electrodes 5 (see FIG. 3).